DE2614973A1 - Electronic automatic control for electromagnetic agitators - uses permanent magnet to trigger field plate sensor with flip flop and logic OR:gate - Google Patents

Abstract

The unit for electronic automatic control of electromagnetic agitators (stirrers) in sealed pressure vessels uses a permanent magnet for switching the working current for the magnet winding, the permanent magnet being fixed to alengthwise movable armature within a pressure tight non-magnetic housing. The permanent magnet triggers a field plate sensor applied externally to the pressure-tight housing, at the upper and lower dead-centres (TDC and BDC) of the armature stroke or throw. The field plate sensor signal is fed via an amplifier to a flip flop and thence via a logic OR-gate to the gate of a thyristor. More specif. a separate multivibrator circuit is used to set the armature stroke frequency, with variation, independent of the main multivibrator's pulse and automatic drive.

Description

Device for electronic self-control of electromagnetic R clock facilities

in closed pressure vessels The operation of electromagnetic stirring devices, a longitudinally movable armature within a pressure-tight, non-magnetic housing from one or two magnet coils attached outside this housing by alternating Switching on and off or

Switching electrical current up and down, or moved back and forth is known, as well as the automatic reversal in the respective end positions.

The German patent specification 1145 712 describes a reversing device by means of the transformer coupling of two pairs of control coils through the longitudinally movable Anchor. The pulse obtained in the respective secondary control coil becomes a Tyratron flip-FI op circuit fed and from there to one oscillating with a fixed fundamental frequency Tubular multivibrator and passed on to the control grid of the work tyratron. In addition to the now outdated electronics, the generation of the control pulse prepared in the control coils most of the trouble. Especially the lower control coils, that are embedded in the middle of the work coil can be prone to interference. There are this disturbance from the main magnetic field, from the temperature of the magnet coil, or total failure due to mechanical effects of the magnetic coil. This has then the consequence that the entire solenoid coil must be unwound to the one below to replace existing control coil.

It also enables; the transformer coupling just a very weak control signal.

These deficiencies are eliminated according to the present invention by that a permanent magnet attached to the longitudinally movable armature in the lower one and top dead center each one attached to the outside of the pressure-tight housing Controls field plate sensors, the signals of which are passed through amplifiers to a flip-flop and from there via a downstream OR gate to the control electrode of the thyristor arrives.

This entire circuit is made with the help of integrated circuits Created in digital technology, which guarantees a very simple structure. The combination of the permanent magnet with the field plate sensors results in very safe and interference-insensitive Switching points. The working method is explained below with the aid of the sketch.

In a known way, the soft iron anchor (1) is pressure-tight through the non-magnetic housing (2) acted upon by the magnetic field of the magnet coil (3) and by switching them on and off, a reciprocating movement of the armature (1) generated. At the upper end of the extended soft iron anchor (1) is located a permanent magnet (4) with its magnetic field on the outside of the housing (2) attached field plate sensor (5,6) is effective. The two field plate sensors (5,6), which are arranged displaceably for the purpose of optimal setting of the reversing points, mark the lowest and highest switching point.

The impulses obtained here are transmitted via the amplifiers (7, 8) to the Flip-flop (9).

From there, the pulse passes through the downstream OR element (10) to the control electrode of the thyristor (11), which controls the working current of the solenoid (3) leads. The type of mains-operated bridge circuit with thyristors is irrelevant. All known circuits are possible.

A retriggerable monostable multivibrator (12) monitors the automatically running stroke cycle and gives the pulses of the basic pulse multivibrator in the event of a malfunction (13) or the AND gates (14) to the OR gates (10) freely.

With the switch (15) = a separate multivibrator (16) can be switched on with a manually adjustable stroke frequency, which is completely independent from the much slower running Grundimpulsmul tivibrator (13) and from automatic mode is working.

A monostable multivibrator attached to the output of the pulse circuit (17) with the following RC element (18) and ammeter (19) enables simultaneous analog lifting speed display.

In the event that one magnet each for the upward and downward movement of the armature is used (stroke-pull-pressure control), both outputs are in each case of the flip-flop, as well as those of the multivibrators with reversed signal to the outside and placed on the respective thyristor groups.

The indicator lights (20,21) signalize that the lower one has been reached and upper end position.

This provides better control and additional help the setting of the hand multivibrator (16) possible.

e e

Claims (6)

Device for electronic self-control of electromagnetic stirring devices in closed pressure vessels, with the circuit of the working current for the solenoid from a pressure-tight non-magnetic Permanent magnet attached to the housing on a longitudinally movable armature, characterized in that the permanent magnet (4) in the lower and upper stroke reversal point a field plate sensor (5, 6) each attached to the outside of the pressure-tight housing (2) controls, the signals of which are passed to a flip-flop via amplifiers (7, 8) and from there via a downstream OR gate (10) to the control electrode of the Tyristor (11) arrives. 2.) Device for electronic self-control of electromagnetic Stirrer devices in closed pressure vessels according to Claim 1, characterized in that that a retriggerable monostable multivibrator (12) the automatically running Stroke cycle Monitors and, in the event of a fault, the pulses from the basic pulse multivibrator (13) Releases via the AND elements (14) to the OR elements (10). 3.) Device for electronic self-control of electromagnetic Stirring devices in closed pressure vessels according to claim 1 + 2, characterized by that a separate multivibrator (16) is independent of the basic pulse and automatic mode adjustable stroke frequency allows. 4.) Device for electronic self-control of electromagnetic Stirring devices in closed pressure vessels according to claims 1 to 3, thereby characterized in that one attached to the output of the pulse circuit monostable Toggle circuit (17) with subsequent RC element (18) and ammeter (19) an analog Lifting speed display enables. 5.) Device for electronic self-control of electromagnetic Stirring devices in closed pressure vessels according to claims 1 to 4, thereby characterized in that for the purpose of stroke-train-pressure control by means of two one above the other arranged solenoid coils, both outputs of the flip-flop (9) and those of the Multivibrators (13, 16) are led out with the opposite signal. 6.) Device for electronic self-control of electromagnetic Stirring devices in closed pressure vessels according to claims 1 to 5, thereby characterized that for the purpose of the end position display in manual operation with the separate Multivibrator (16) arranged behind the amplifiers (7, 8) indicator lights (20, 21) are.